2031 research outputs found
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Effects of Varied Soil Leveling Methods on Physical Properties: A Comparative Analysis
Get PDFThe total cultivated land area in this context is 8,664,000 square meters, which constitutes about 4% of Egypt's territory. The cultivation relies on old land dams, lines, and furrow surface irrigation systems. A significant portion (76%) of the cultivated land is irrigated with high-density leveled soil instead of unlevelled soil. Leveled soil has very low clay and organic matter content. Land leveling is a preparation or modification process that provides a suitable surface for seeding production. It involves reducing high areas and raising low or deep spots to create a more even surface. Laser-controlled land leveling is a technique that helps create a more even surface by reducing high areas and raising low spots. This process aims to eliminate surface irregularities and create a level plane, which can significantly impact crop germination, uniformity, and, ultimately, the yield of field crops. Laser technology allows for precision in land leveling, ensuring a more consistent seed depth, better water distribution, and improved crop-growing conditions. By creating a more uniform surface, the potential for more consistent crop growth, better water retention, and improved distribution of nutrients is increased. The study's main objective appears to be to determine the most appropriate types of land leveling that can be implemented and to analyze how land leveling treatments affect the physical properties of the soil during different seasons. The data shows that the leaser treatment decreased soil porosity in both seasons, dropping values from 57.36% to 54.34% in the first season and from 55.47% to 51.32% in the second season. In contrast, the "rotary treatment" had the opposite effect, increasing soil porosity in both seasons. The values rose from 57.34% to 59.62% in the first season and from 57.74% to 59.25% in the second. Observing how these treatments had different impacts on the soil over time is intriguing. Doi: 10.28991/CEJ-2024-010-11-014 Full Text: PD
Stress Concentration Factors in KT-Joints Subjected to Complex Bending Loads Using Artificial Neural Networks
Get PDFFatigue analysis of tubular joints based on peak stress concentration factor (SCF) is critical for offshore structures as it determines the fatigue life of the joint and possibly the overall structure. It is known that peak SCF occurs at the crown position for in-plane bending (IPB) and at the saddle position for out-of-plane bending (OPB). Tubular joints of offshore structures are under multiplanar bending, comprising IPB and OPB. When a joint is subjected to IPB and OPB loads simultaneously, the peak SCF occurs somewhere between the crown and the saddle. However, existing equations estimate SCF at the crown and saddle only when a joint is subjected to IPB or OPB. It was found that the position and magnitude of peak SCF under simultaneous IPB and OPB depend on the relative magnitudes of these uniplanar load components. The crown and saddle position SCF can be substantially lower than the cumulative peak SCF. Empirical models are proposed for computing peak SCF for KT-joints subjected to multiplanar bending. These models were developed through regression analysis using artificial neural networks (ANN). The ANN training data was generated through 3716 ANSYS finite element simulations. The empirical model was validated using models available in the literature and can determine peak SCF with an error of less than 1.5%. Doi: 10.28991/CEJ-2024-010-04-04 Full Text: PD
Geotechnical Properties of Fly Ash Blended Expansive Soil: A Review
Get PDFFly ash, an industrial byproduct, is used as both a building material and a soil stabilizer due to its pozzolanic properties. Moreover, it is challenging to extrapolate the results based on an inadequate amount of laboratory data because of the non-homogeneous character of the soil and the diversity in the chemical properties of fly ash. This review article fills in the gaps by providing an overview of the existing data related to the geotechnical characteristics of expansive soil stabilized with fly ash. The chemical composition of fly ash is provided in terms of oxides of various elements to help identify the kinds produced in different nations. Additionally, information about the physical and geotechnical characteristics of fly ash blended expansive soil is provided in order to comprehend the influence of the fly ash's chemical composition and the expansive soil's fines percentage. While the geotechnical property comprises Atterberg's limit, compaction, UCS, shear strength, free swelling index, CBR, and consolidation, the physical property includes specific gravity and durability. Shear modulus, damping ratio, and Poisson's ratio are used to describe the dynamic properties of the modified expansive soil. The published data in this field and the research gap will be identified by the researchers with the aid of this article. Doi: 10.28991/CEJ-SP2024-010-06 Full Text: PD
Geopolymers: Enhancing Environmental Safety and Sustainability in Construction
Get PDFThis study underscores the significant environmental advantages of geopolymer, notably its capacity for substantial CO2emission reduction and sustainable waste management by repurposing industrial by-products, enhancing the environmental safety in oil and gas projects. Central to our investigation is the identification and strategic overcoming of critical obstacles to the broader application of geopolymer, aiming to bridge the gap between its recognized potential and practical implementation in construction practices. Through a comprehensive analysis involving pilot, main, and validation surveys among construction industry professionals, we employed exploratory factor analysis (EFA) and structural equation modeling (SEM) to elucidate the relationships between various barriers and the success of geopolymer concrete applications. Our findings reveal that standards and knowledge significantly influence the adoption of geopolymer concrete, with an R² value of 0.873 indicating a high predictive utility of these constructs. The research underscores the critical need for enhanced support in research and development to improve geopolymer concrete's durability and performance over time. Significantly, this study contributes novel insights into overcoming the industry's hesitancy towards geopolymer concrete, highlighting its importance for sustainable construction practices and reducing the environmental footprint of building materials. Doi: 10.28991/CEJ-2024-010-10-015 Full Text: PD
Development of a Conservative Hamiltonian Dynamic System for the Early Detection of Leaks in Pressurized Pipelines
Get PDFIn this study, we propose an innovative approach for real-time leakage detection in pipelines by integrating conservative Hamiltonian equations and experimental Internet of Things (IoT) technologies. The proposed method combines a hybrid model that utilizes sensors and IoT devices to acquire real-time data and solves the coupled system of Hamiltonian equations using the ODE45 numerical integration method. Spectral frequency analysis is an essential part of this method, as it reveals specific patterns in the pressure and flow signals. The findings highlighted 95% accuracy in leak detection, which was validated through a comparison of the theoretical and experimental data. The novelty of this approach lies in its ability to maintain constant total system energy, thereby enabling continuous monitoring for early leak detection. As an improvement, the proper handling of sensor signals is emphasized, underscoring its contribution to the efficient management of water resources in potable water distribution systems. Doi: 10.28991/CEJ-2024-010-04-01 Full Text: PD
Applying Harmony Degree Equation and TOPSIS Combined with Entropy Weights in Surface Water Classification
Get PDFThis study classified surface water quality in Can Tho city using the Eutrophication index, Harmony Degree Equation (HDE), and Technique of Order Preference by Similarity to Ideal Solution (TOPSIS). Water quality data were collected in two seasons at 38 locations with 18 parameters, including temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), nitrite (N-NO2-), nitrate (N-NO3-), ammonium (N-NH4+), orthophosphate (P-PO43-), Fe, F-, Pb, As, Hg, coliform, chlorine-, and phosphorus-based pesticides. Water quality parameters are compared with national technical regulations on surface water quality (QCVN 08-MT:2015/BTNMT). The HDE method based on entropy weight has been applied to evaluate the comprehensive harmony degree of water quality for various purposes. In addition, the TOPSIS was also used to rank water quality at each location and determine the priority level that required mitigation and treatment solutions. Surface water quality in the study area had low dissolved oxygen content and was contaminated with TSS and coliform in both seasons. Water quality in the rainy season tends to decrease compared to the dry season. Based on HDE results, water quality in the study area in the dry season was assessed as suitable for domestic activities (needs treatment), irrigation, and navigation (HDII = 0.922), while the rainy season was suitable for irrigation and navigation (HDIII= 1.00). Moreover, surface water in the study area was in a state of potential eutrophication (EI > 0), in which eutrophication was higher during the dry season. The SW25 and SW28 were the most seriously eutrophic in the dry and rainy seasons, respectively. TOPSIS analysis indicated that SW22 and SW28 need treatment measures in both seasons; furthermore, SW2-SW4 (dry season) and SW23 (rainy season) also need appropriate management and impact mitigation solutions. SW4 was affected by the most significant seasonal impacts, which have high priority in the dry season and are lowest in the rainy season. Therefore, future studies are needed to identify specific sources of variation at these locations to reduce impacts. The study results provide helpful information for the decision-making process and water quality management. Doi: 10.28991/CEJ-2024-010-04-012 Full Text: PD
Performance Index Model of Raw Water Infrastructure
Get PDFThis research intends to build a performance index model of raw water infrastructure mathematically by considering technical, non-technical, and environmental aspects. The research location is in Lombok and the Sumbawa Islands. Data is collected by field surveys and questionnaires that are distributed to 160 respondents related to raw water infrastructure in 21 locations. The methodology consists of Partial Least Squares (PLS) and Generalized Reduced Gradient (GRG). The results show that technical, non-technical, and environmental aspects have a significant influence on the performance index of raw water infrastructure. The structural analysis shows that the technical, non-technical, and environmental variables have a positive and significant influence on the performance index. The performance index of raw water infrastructure is successful enough to be developed and tested by using field data and GRG. The evaluation result shows that the model gives an accurate estimation of raw water infrastructure performance in Nusa Tenggara Barat province. The performance index model for raw water infrastructure is as follows: 0.521 IKTK + 0.305 IKNT + 0.174 IK Liwith the sum of square residual (SSR) is 83.21, the root mean square error (RMSE) is 0.44, the mean square error (MSE) is 3.97, and the accuracy level is 95.25%. This research provides the development of an evaluation method for raw water infrastructure performance and a valuable outlook for policymakers in managing and maintaining raw water infrastructure to support sustainable water resources in the future. Considering some aspects of this, it is hoped the efforts to increase the quality of raw water infrastructure can be more directed and effective, contributing to increasing society's prosperity and a sustainable environment in the region. Doi: 10.28991/CEJ-2024-010-06-014 Full Text: PD
Investigation of the Mechanical Behavior of Full-Scale Experimental Bugis-Makassar Timber House Structures
Get PDFThe Sulawesi region is located at the confluence of a smaller Philippine plate and three major global plates, namely the Indo-Australian, Pacific, and Eurasian. This strategic location makes Sulawesi and the surrounding earthquake-prone region in Indonesia. Recognizing the seismic vulnerability of this region, various measures, such as the use of houses on stilts, have been explored to enhance earthquake resistance. These structures are designed to avoid direct exposure to seismic energy, according to several reports on Indonesian earthquakes. In the last two years, an in-depth investigation has been carried out to analyze the behavior and resistance of Bugis Traditional Houses to earthquakes. Although simulation and computational studies are still in progress, the results show that Bugis-Makassar House on stilts maintains an elastic state with a high level of performance. Therefore, this study aimed to investigate the mechanical behavior of Bugis-Makassar stilt house structures using full-scale tests. During the investigation, experimental testing was conducted using house specimens measuring 1.5í—2.3 m in the laboratory. A cyclic lateral loading analysis was performed using ISO 16670-2003 as a guide. The results showed that cyclic lateral loads caused house structures to sway, while the timber experienced minimal damage. Both the hysteresis energy, EH to EI, and the energy conversion ratio, GPE to ESE (ER), were found to be approximately balanced. This equilibrium suggested that seismic energy can be cyclically stored and released to reduce damage to structural elements. Doi: 10.28991/CEJ-2024-010-06-04 Full Text: PD
Strength and Acid Resistance of Mortar with Different Binders from Palm Oil Fuel Ash, Slag, and Calcium Carbide Residue
Get PDFThis study deals with the use of ground palm oil fuel ash (GPOFA) in combination with ground granulated blast furnace slag (GGBFS) and ground calcium carbide residue (GCR) to produce the binary and ternary binders-based alkali activated mortar. The appropriate content of materials in each binder type was determined as a function of compressive strength. The results revealed that both GPOFA:GGBFS and GPOFA:GCR binders had an optimum blending ratio of 70:30 wt%, while the GPOFA:GGBFS:GCR binder was 55:30:15 wt%. An alkaline catalyst of NaOH was admixed to the best mixture in each binder type to stimulate the mortar's compressive strength. The sulfuric acid (H2SO4) resistance of the mortar in terms of weight change was also examined. The addition of 1M NaOH in both binary and ternary binders could enhance the compressive strength and H2SO4 resistance of the mortar. The highest compressive strength and lowest weight change due to soaking in H2SO4 solution were found in the ternary binder mortar with a 1 M NaOH. The mortar with GCR immersed in H2SO4 solution resulted in an increased weight, which was different from that of the mortar without GCR. The microstructural analysis of the alkali-activated pastes indicated more reaction products than in the case of the pastes without alkali activator. However, a higher concentration of 2 M NaOH resulted in a poor microstructure, which had a negative effect on the compressive strength and H2SO4resistance. Doi: 10.28991/CEJ-2024-010-07-08 Full Text: PD
Load Capacity and Bending Strength of Double-Acting Friction Stir Welded AA6061 Hollow Panels
Get PDFAluminum alloy hollow panels are essential components in both civil and mechanical structures, such as building floors or large vehicle platforms. They enhance rigidity while staying lightweight and conserving material volume. In its application, this panel must be joined using welding methods. One common issue encountered in aluminum welding is the formation of porosity defects. Solid-state welding methods like Friction Stir Welding (FSW) can be a solution to address this problem. The FSW joining process on hollow panels cannot be completed in one welding operation due to their thickness. The FSW process must be performed on both surfaces, which requires a relatively long time. Therefore, FSW needs to be developed into a Double-acting FSW that utilizes two tools simultaneously. These two tools introduce two sources of heat input, pressing force, and friction-stirring, resulting in a novel response that needs further research. This study delves into the impact of welding speed variations in Double-Acting FSW on the load capacity and bending strength of AA 6061 hollow panel joints. Welding speeds of 20, 30, and 40 mm/min were tested alongside rotational speed (1500 rpm), tilt angle (2°), and shoulder diameter (24 mm). It was discovered that reducing welding speed enhances both load capacity and bending strength. Notably, specimens welded at 20 mm/min exhibited a load capacity of 15.61 kN and bending strength of 52 MPa, highlighting the potential of slower speeds for superior weld performance. Doi: 10.28991/CEJ-2024-010-08-018 Full Text: PD